Signaling system and mechanism therefor



Oct. 13, 1936. E. R. FREEBERG 2,057,186

SIGNALING SYSTEM AND MECHANISM THEREFOR Filed Feb. 7, 1934 3Sheets-Sheet 1 41 54: 4?: 57 fi5: 2 M a a s 2 TD F 0 WEI? SUPPLYINVENTOR ERNEST P2. FREEBERG ATTORN EY Oct. 13, 1936. FREEBERG 2,057,186

SIGNALING SYSTEM AND MECHANISM THEREFOR Filed Feb. 7, 1954 5Sheets-Sheet 3 TU PUWEP SUFPLY fist- 9 INVENTOR ERNEST R. FREEBERGATTORNEY Patented Oct. 13, 1936 UNITED STATES PATENT OFFICE SIGNALINGSYSTEM AND MECHANISM THEREFOR chusetts Application February 7, 1934,Serial No. 710,151

7 Claim.

This invention relates to signaling systems in which visual or othersignaling aspects are alternatively or successively given, and isparticularly suited for embodiment in signaling systems for controllingand directing vehicular highway traffic.

The rate of movement of vehicles upon main or so-called arterialhighways has increased during the past decade to so great an extentthat,

10 if warning is merely given to drivers of vehicles that the right ofway has been withdrawn from the highway upon which they are travelingand has been given to those who are likely to cross their path, Vehicleswhich are approaching the crossing point or intersection at a time whena stop indication is given for them, are likely to be moving so rapidlythat they will be unable to bring their vehicles to a stop beforereaching the intersection; and, hence, will unavoidably enter upon orcross same at a time when the vehicles or pedestrians who have beengiven a "procecd signal have moved into their path.

The situation thus developed is aggravated by the psychological tendencyto attempt to get across the intersection without being delayed by thepassage of traflic which is waiting to move across the path. Thus, ithas been found that if, in a cycle of signal changes, an interval isprovided for clearing the intersection during which so stop" signalingaspects for all trafllc are displayed, drivers of approaching vehiclesare prone to rely on such supposed period of grace when the stop signalappears, and to therefore speed up instead of slowing down their rate ofmovement. In fact, the result seems to be that inasmuch as they arepermitted to pass the stop signal for at least a short interval after itappears, they arelikely to misjudge, to a greater or less extent, thetime when other trafhc will have actually moved into their path,depending upon the differing degrees of their impatience upon variousoccasions, so that there comes an occasion when they reach the crossingor point of intersection at the very time it is occupied by another,while traveling at an especially rapid rate, thus intensifying theseriousness of the consequences.

If the development of such situations is to be prevented, it appearsindispensable that when a highway trairlc signal displays such a stopaspect, all approaching vehicles shall be required to stop short of it.However, in order to make it possible for the drivers of vehicles to dothis, it is essential that warning shall be given them for a time inadvance of the display of the stop indication which is sufiicient forthem to arrest their movement before they reach the signal; and it is,of course, equally essential that such warning shall be of a kind whichis calculated to be understood by all drivers having ordinary 5comprehension of the significance of the various aspects of highwaytrafiic signals.

It is a further object to provide a trafllc control signal display whichflashes either a stop" or a go" signal for intervals of progressivelyde- 10 creasing duration and/or for durations separated by intervals ofextinguishment of progressively decreasing duration.

In instances wherein a signal is flashed with progressively decreasingdurations of the interl5 vals between flashes, the durations of thedisplays themselves being substantially unchanged,

a resulting characteristic signal display is ob tained which gives anopposite visual impression from that given in instances whereindurations 20 of the flashes are progressively decreased and thedurations. of the intervals between flashes are held eithersubstantially constant or are also progressively decreased.

In the first instance the ratio of duration of 25 intermittent signaldisplay with relation to the duration the intervals between suchdisplays, increases so that the display approaches a continuous one.

Such increased ratio has a very desirable effect 30 on the movements oftraflic when such intermittent display applies to the red or stopsignal.

For example, the driver of a vehicle approaching an intersection andobserving a flashing red signal, with the red display seemingly becoming35 more and more prominent, is not only psychologically urged to be onthe alert for a change in signals, but is also given what might well betermed a subconscious suggestion that he should bring his vehicle to astop even though 40 he knowns the green signal may persist long enoughfor him to get across.

As a result of such urge, drivers of vehicles are more likely to retardtheir speed at intersections and not attempt to beat the light.

Furthermore, when the green or go light is flashed in accordance withthe second instance,

1. e., with the durations of flashes progressively decreased either withor without decreases in the durations of intervals between such flashes,another desirable psychological urge is presented which tends to causedrivers to stop their vehicles due to the decrease in the amount ofdisplay of the "go signal. As a result of the tendency Just 55 setforth, drivers of vehicles are deterred from attempts to beat the light.

It is, therefore, a general object of this invention to provide asignaling system and mechaniism therefor whereby a warning will be givenwhen the signaling aspect is about to change, and in which such warningwill be given by intermittently displaying or indicating a signalingaspect about to become efiective.

It is a more specific object of this invention to display such a warningin a manner which will progressively indicate the increasing proximityof the time when the impending change will become effective.

Further objects are to provide embodiments of this invention which maybe inexpensively produced, which will be durable, readily understood andwill require a minimum of attention for purposes of maintenance, andwhich facilitate utilization of existing installations with a minimum ofrevision and extension.

For better understanding of this invention, reference may be had to theannexed drawings and the detailed descriptions thereof hereinaftercontained, in which certain embodiments of this invention areillustratively indicated; however, it should be understood that althoughthe embodiments so indicated are practical, they are by no means theonly ones which this invention may assume, and they are given withoutintent to imply limitation to the particular details and arrangementstherein shown, except insofar as such details and arrangements aredefined in the appended claims.

Similar reference characters indicate corresponding parts in theaccompanying drawings, in which Figure 1 diagrammatically indicates asimplified form of so-called pre-timed" highway traffic signalingequipment, embodying an aspect of this invention;

Fig. 2 correspondingly indicates the manner of applying another aspectof this invention to such a system;

Fig. 3 similarly indicates another embodiment of this invention forsupplying results corresponding to those afforded by the system of Fig.2;

Fig. 4 is a chart indicating the relative duration and times ofoccurrence of the color periods incident to a cycle of the operation ofthe system indicated by Figs. 1, 2 and 3;

Fig. 5 indicates the application of this invention to signalingequipment suited for response to vehicle or pedestrian movements and/orsubject to coordination of activity with other signaling equipment; and

Figs. 6, 7, 8 and 9 are charts indicating the rel ative duration andtimes of occurrence of color periods which may be provided, inaccordance with this invention, by revision of the movement, formation,arrangement and manner of connecting the cams and contacts of Figs. 1,2, 3 or 5.

Referring to Fig. 1, a so-called traflic signal controller is generallyindicated at C and a group of signal lights situated at a highwayintersection is correspondingly indicated at S The controller indicatedat C is illustrative of any one of various well-known types of trafficsignal controllers which comprise circuit controlling mechanism andactuating means therefor. In this schematic illustration, the actuatingmeans is exemplified by the motor 2| which acts through the gears 22 and23 to drive the shaft and the circuit controlling mechanism isexemplified by the cams 3", 32 33 and 34 which are driven by the shaft24 and the pairs of circuit controller contacts 42 43 and which areoperatively associated with said cams, respectively.

The signal lights R R G G are provided for governing the movement oftraffic which approaches the intersection along the vertically disposedone of the indicated highways which, for convenience, is designated bythe word Main and the lights R, R, G, G are provided for governing themovement of traffic which approaches the intersection along the other ofthe indicated highways which, for convenience, is designated by the wordCross".

It will be understood by those skilled in this art that the controller Cmay include facilities whereby adjustments may be readily effected ofthe time intervals which intervene between recurrences of givensignaling aspects in the cycle of the operation of the controller aswell as in the relative proportions of such cycle time which areallotted to one and the other of the alternate signal manifestations,for coordinating the activities of two or more of such controllers, forrendering the controller responsive to tramc movements in one or more ofthe affected trafllc channels, and for controlling and regulatingtraflic movements at intersections involving more than two highways orthoroughfares, besides providing facilities for meeting other of themultifarious situations presented by the various phases of trafliccontrol problems; however, such facilities are here omitted in theinterest of simplicity and clearness, as it is believed that thoseskilled in this art are familiar with expedients whereby suchcharacteristics may be readily associated to a needful extent in acontroller embodying the aspect of this invention to which Fig. 1 isparticularly directed.

The conductors 5H and 52 connect the motor 2l with the power supply; theconductor 53 connects conductor 52 with one terminal of each of thelamps R R R ,R ,G 6", G G; the conductor 54 connects the conductor 5|with one of the contacts of each of the pairs of circuit controllercontacts M 42 43 and the conductor 55 connects the other of the pair ofcircuit controller contacts with the lamps R R and the conductors 56 51and 58 correspondingly connect the remaining contacts of the pairs 42 43and 44 with the lamps R", R ;G G ;and G G= ;-respectively.

The cam 3" is so formed as to continuously permit closure of thecontacts 4 I during approximately one-half of each revolution of theshaft 24 and the cam 32 is so formed as to permit continuous closure ofcontacts 42 during the remainder of each revolution of the shaft 24 Thecam 33 is so formed as to cause continuous separation of the contacts 43throughout all of that half of each revolution of the shaft 24 duringwhich cam 3| permits continuous closure of the contacts M and the cam 34is so formed as to cause continuous separation of the contactsthroughout all of the other half of each revolution of the shaft 24 Fromthe foregoing it will be apparent that during approximately one-half ofeach revolution of the shaft 24 the contacts 43 will be continuouslyclosed, thus causing the lamps G G to be lighted and to thereby providea go" signaling aspect for the traflic approaching the intersectionalong the Main" thoroughfare; and that, during the remainder of eachrevolution of the shaft 24 the contacts will be closed so that the lampsG, G will be lighted, to thereby provide a go signal for trafficapproaching the intersection along the Cross thoroughfare. It willfurther be evident that so long as contacts 43 are closed, contacts 42will also be closed, thereby providing a stop signal for trafficapproaching the intersection along the Cross" thoroughfare throughoutthe time that a go signal is provided for traific approaching theintersection along the Main thoroughfare; and, correspondingly, whenevercontacts 44 are closed, contacts will also be closed, therebycorrespondingly providing a stop signal for traflic approaching theintersection along the Main thoroughfare throughout the time that a gosignal is provided for traffic approaching the intersection along theCross thoroughfare.

A group of teeth 3| l is formed in the periphery of cam 3| in suchposition that they will be carried past the co-engaging one of thecontacts just after the main or continuously raised portion of said cam3I has withdrawn therefrom incidental to counter-clockwise rotation ofsaid cam, to the end that when the contacts have been held continuouslyopen by the main raised portion of the cam 3H, and while the cut-awayportion of the cam 33 is still being presented to the contacts 43 thenotches between the teeth 3| I will permit a series of closures of thecontacts so that the red or stop signal lamps R R will repeatedly flashjust prior to the extinguishment of the green or go signal lamps G G andjust prior to the continuous lighting of the lamps R R which occurswhile the cut-away portion of cam 3| is presented to contacts A similargroup of teeth 32H is formed in the periphery of cam 32 for likeactuation of contacts v42 so that the lamps R R will be caused torepeatedly flash during burning and just prior to extinguishment of thelamps G G.

The times of the occurrences of changes in the signaling aspectseffected by the lighting and extinguishing of the signal lamps. withrelation to the contours of the cams, is further illustrated by thechart of Fig. 4, which is representative of one revolution of shaft 24and hence one cycle of the operation of the mechanism.

In this chart, the upper band RR is representative of the red lamps R Rof Fig. 1, and the band directly below same marked GG is representativeof the green lamps G, G, all of which lamps are provided for controllingthe movements of Main" highway traffic.

The shaded portions of these bands indicate the times during the cyclewhen the lamps of the represented group are lighted, and the blankportions of these bands represent the times when these lamps areextinguished.

The line 3I0 is a development along a horizontal plane of the peripheryof the cam 30, and the line 330 is a corresponding development of theperiphery of the cam 33 The bands RR and GG correspondingly representthe lamps R R and G, G of Fig. 1, and the associated lines 320 and 340correspondingly represent the peripheries of cams 32 and 34 01 Fig. 1.

The operation of the system of Fig. 1 is as follows:

Upon application of a suitable source of power supply to the conductorsSH and 52 the motor 2I will run and, through the action of the reductiongearing 22 23 will cause rotation of the shaft 24 at the desired speed,so that the time occupied by each revolution of this shaft will be thatdesired for a cycle of signaling aspects.

Assuming that, at the time of the application of electrical energy tothe conductors 5| and 52 the shaft 24 is so positioned that the raisedportions of cams 3N and 34 have just been withdrawn from theirassociated contacts, the lamps R R1111 will be lighted, thus providing astop aspect to traflic approaching the intersection along the Mainthoroughfare, and the lamps G G will be lighted, thus providing a goaspect to traflic approaching the intersection along the Crossthoroughfare.

With cams formed as shown in Fig. 1, such aspects will continue forapproximately one-half of a revolution of the shaft 24 However, duringthe latter portion of such half revolution, contacts 42 will bepermitted to momentarily close through presentation of the notch betweenthe continuous raised portion of cam 32 and the first of the teeth 32 Iwhereupon the lamps R R will be lighted. When the shaft 24 is thereuponrotated for a slight additional distance, the first of the teeth of thegroup 32 I will cause separation of the contacts 42 and consequentextinguishment of the lamps R, R. This action will be repeated as thenotches between the others of the teeth of the group I'I'M are presentedto the contacts 41".

Through the resultant flashing of the lamps R, R, drivers of vehiclesapproaching the intersection along the Cross thoroughfare, who wouldotherwise reach and fail to clear the intersection after a "go signalingaspect had been given to Main thoroughfare trafiic, will be givenwarning preceding the impending signal change by a time such that theywill have opportunity to stop their vehicles before reaching theintersection.

As the last of the teeth of the group 31H is withdrawn from the path ofthe co-engaging one of the contacts 42 the raised portion of the cam 34will cause separation of the contacts 44 so that lamps G, G will beextinguished at the commencement of the interval during which lamps R Rare continuously lighted. At the same time, the raised portion of cam 33will be withdrawn from the co-engaging one of the contacts 43 and theraised portion of the cam 3l will cause separation of the contacts 41thereby causing the lighting of the lamps G G and the extinguishment ofthe lamps R R Thus there will be provided a stop signaling aspect fortrafiic approaching the intersection along the Cross thoroughfare and ago signaling aspect for trafiic on the Main" thoroughfare.

Thereafter, during further rotation of the shaft 24 the signaling aspectjust described will continue until the notch preceding the first of theteeth of the group 3H permits closure of the contacts 41 whereupon thelamps R R will be flashed, and a warning signal will be given fortraflic approaching the intersection along the Main thoroughfarecorresponding to that already described as resulting from the actuationof contacts 42 by the notches between the teeth of the group 32l Whenthe last of the teeth 3| I has been thus withdrawn from the path andthereby permitted closure of the co-engaging one of the contacts M thelamps R R will be continuously lighted; the raised portion of the cam 33will cause extinguishment of the lamps G G by separating the contacts 43the raised portion of the cam 34 will be withdrawn from the co-engagingone of the contacts 44 thereby causing lighting of the lamps G, G; andthe raised portion of the cam 32 will cause separation of the contacts42 sothat lamps R, R will be extinguished. Thus there will be provided astop signaling aspect for traflic approaching the intersection along theMain thoroughfare and a go" signaling aspect for trafiic on the Crossthoroughfare.

If, for any reason, it is desired to provide such a flashing signal forwarning the traflic approaching along one of the highways, withoutproviding a corresponding signal for traffic approaching along the otherhighway, a continuation of the raised portion may be substituted for oneor the other of the groups of teeth 32F, 3H I It is evident from theforegoing, that, as indicated by the chart of Fig. 4, the warningflashes resultant from operation of a system such as that of Fig. 1, andall the intervals therebetween, will be of substantially uniformdurations, respectively. However, it is believed to be distinctlyadvantageous to provide a larger number of flashes for such a warningsignal, than can (for reasons believed to be well understood by thoseskilled in this art) be readily provided for with an arrangement such asis indicated by Fig. 1, and it is further desirable to cause suchflashes to occur at a progressively increasing rate, or, in other words,with progressively decreasing intervals therebetween.

The arrangement diagrammatically indicated by Fig. 2 accomplishes theresult of thus progressively decreasing the interval between the flashesof each group, as well as increasing the number of flashes in the group,while permitting a construction as compact and sturdy as that indicatedby Fig. 1.

The lamps R R G G RF, RF, 65, of Fig. 2, correspond to the similarlydesignated lamps of Fig. 1.

In the controller C of Fig. 2, the motor 2|", the reducing gearingrepresented by 22 23 the shaft 24 the cams 33 and 34 the contacts M 4243 and 44 and the conductors 5| and 58 inclusive, correspond withsimilarly indicated parts of Fig. 1.

The cams 3| and 32 are similar in contour to the cams 3H and 32 otherthan in that continuations of the raised portions are substituted forthe groups of teeth 3 and 320, respectively. The cam 3P carries a pin3l2 and the cam 32 carries a pin 32!, the purposes of which pins will behereinafter more fully explained.

The cam 35 is fixed upon the shaft 24 and cooperates with the contacts45 and 46 so that, during substantially one-half of each revolution ofsaid shaft, the cam 35 will permit closure of the contacts 45 and holdthe contacts 46 open, and throughout a corresponding portion of theother half of each revolution of said shaft said cam will permit theclosure of the contacts 46 and hold contacts 45 open.

An auxiliary shaft 6|? hasthe pinions 62 and 63, and the ratchet wheel64 fixed thereon, and the toothed wheel 65 is loosely journaled uponsaid shaft. The ratchet dog 61 is pivotally mounted upon the wheel 65the free end of said dog being urged into engagement with the teeth ofratchet wheel 64 by the spring 68.

The contact. H is tensioned for movement toward, and the free endthereof is disposed in the path of the teeth of the wheel 65*, so that,upon rotation of said wheel, said contact will be moved into and out ofengagement with the contact 12 The teeth of the wheel 65 vary in pitchfrom widely spaced teeth such as the teeth 13 and 14, to closely spacedteeth such as the teeth 15 and 16; so that, upon counter-clockwiserota.- tion of said wheel at substantially uniform rate, from theposition where tooth 13 engages contact H to that in which tooth 16engages said contact, the intervals between engagements of adjacent onesof said teeth will be of progressively decreasing duration.

The conductor 8! connects contact H with conductor 54 the conductor 82connects contact 12 with one of the contacts 46; conductor 83 connectsconductor 82 with one of the contacts 45; conductor 84 connects theother'one of the contacts 46 with conductor 56 and conductor 85 connectsthe other of the contacts 45 with conductor 55 The rack bars 9! and 92engage the pinions 62 and 63, respectively; these bars being supportedby studs 94 94 94 94 which project through slots 95 permittinglengthwise movement of said bars while engaging their respectivepinions, for imparting desired rotation to the auxiliary shaft 6lInasmuch as the bars 9| and 92 are interconnected through the shaft 6|and their associated pinions 62 and 63, respectively, each will respondto actuation of the other.

The springs 96 96 are applied to the bars 9| and 92 for lifting them tothe limit of movement permitted by their supporting studs 94*, and theupper ends 91, 91, of said rack bars extend into the paths of the pins3l2 and 322 respectively, so that, when the shaft '24 is rotated by themotor 2 l the pins 3l2 and 322 will each, one after the other, engageand then disengage its respective rack bar, thereby efiectingsimultaneous movement of said rack bars against the tension of theirassociated springs 96*, 96 The arrangement of said bars 9! and 92 withrelation to the paths of movement of said pins in and 322 respectively,is such that, when one or the other of said pins engages its associatedrack bar, it will move same to an extent such as will cause onerevolution of the auxiliary shaft 6! and will then move out of the pathof the cooperating end 91 of such bar, whereupon the parts will bereturned to their normal position by the springs 96 96 The pin am is sosituated with relation to the raised portion of the cam 3P, that saidpin will engage the bar 9| during intended counterclockwise rotation ofthe shaft 24 sufliciently in advance of the withdrawal of the raisedportion of said cam from engagement with the con-- tacts 4|, that theresultant rotation of the auxiliary shaft 6| 2 will have been completedjust before the raised portion of the cam 3l is withdrawn to therebypermit the contacts 4 P to close. The pin 322 is correspondingly locatedwith reference to the raised portion of cam 32.

The cam 35 is so positioned upon the shaft 24 as to permit closure ofthe contacts 45 throughout actuation of the rack bar BI by the pin 3l232', 33, 34 and 35'. The resulting lighting and extinguishment of thelamps of signal S will correspond to that hereinbefore described inconnection with Fig. 1, insofar as the continuous lighting andextinguishment of said lamps is concerned; however, the flashing of thered lamps shortly before the extinguishment of their associated greenlamps is accomplished in a distinctly different manner, as will now bedescribed.

Assuming that the cam 33 has permitted the contacts 43 to remain closeduntil a time when the "Main" thoroughfare red lamps R lt should commenceflashing, the pin 3|2' will be carried into engagement with the upperend 91 of the bar 3|", so that the continued rotation of shaft 24 willcause said bar to move downwardly in engagement with pinion 32, andthereby rotate shaft 6i.

Such rotation of shaft 8i will cause ratchet wheel 34 to drive wheel65', acting through ratchet dog Bl, in a counter-clockwise direction.thereby consecutively bringing the teeth of wheel 85' into engagementwith contact ll", so as to repeatedly move same into engagement withcontact 12'. Throughout such rotation of wheel the cam 35 will permitclosure of the contacts the various parts being shown in Fig. 2, aspositioned approximately midway the rotation of shaft 6| responsive tothe movement of rack bar 3| by pin 3l2". Upon each closure of thecontacts II and 12', a current path will be established from conductor5P, through conductor 54*, conductor 8|, contacts H and I2, conductors82 and 83, contacts 45, conductor 85, conductor red lamps R R conductorl3 to conductor 52". It is therefore evident that the lamps R R will bebriefly lighted or flashed" during the successive engagements of thevarious teeth of the wheel 65*, and that, during the rotation of suchwheel, the intervals between such flashes will progressively decrease,due to the progressive decrease in the spacings between such teeth. Itwill also be evident that the durations of the flashes will besubstantially uniform.

Following the disengagement of tooth 16 from contact H pin 3I2 will becarried by cam 3| out of the path of the upper end 91 of bar 9|,whereupon springs 96', 96 will act through bars 3" and 32 to causeclockwise rotation of shaft 6| to an extent corresponding to thecounterclockwise rotation imparted to said shaft through actuation ofthe bar ill by the pin 3l2=.

The wheel 6."! will not rotate with the shaft 6| during such clockwisemovement, being permitted by the dog 61 to remain in the position wherethe contact ll rests between the teeth 16 and 13, contact 1| thus beingout of engagement with contact 12 Immediately following the terminationof the counter-clockwise rotation of the wheel 65, the rise of the cam33 will act to separate contacts 43 and thus cause extinguishment oflights G", G, and the rise of cam 3| will be withdrawn so as to permitcontacts 4| to close and thereby effect continuous lighting of the lampsRP, R whereby a stop signaling aspect is given to trafllc approachingthe intersection' along the Main thoroughfare. At substantially the sametime, the rise of cam 32 will effect separation of contacts 42 and thusextinguish lamps R R, and the rise of cam 34 will be withdrawn andthereby permit closure of contacts 44, and thus cause lighting of thelamps G, G", so as to provide a "go" signaling aspect for the Crossthoroughfare.

In the course of subsequent rotation of the shaft 24', the rise of cam35 will effect separation of contacts 45, and will be withdrawn andpermit closure of contacts 46; after which, in suitable timed relationprior to release and consequent closure of contacts 43 and 42 by cams 33and 32", respectively, pin 322', carried by said cam 32', will engagethe upper end 9! of bar 32', and thereby cause rotation of shaft 6i andresultant operation of contact H as hereinbefore more fully explained.

During such operation of contact ll, resultant from engagement of pin322 with the upper end 91 of bar 92', each time that said contact II ispressed against contact I2 a current path will be established fromconductor ii, through conductors 54' and 8|, contacts II and 12,conductor 32, contacts 46, conductors 34 and 58', through lamps R, R",and conductor 53 to conductor 52; thereby causing the lamps R,

-R, to be flashed during the engagement of each of the teeth of thewheel 35, as hereinbefore more fully described.

From the foregoing, it will be evident that the general results of theoperation of a signaling system arranged in accordance with Fig. 2 issubstantially the same as is indicated in the chart in the upper portionof Fig. 4, except that the red flashes will be more numerous, and willbe separated by intervals of progressively decreasing duration, asexemplifled by the band 2, of the chart of Fig. 4 which shows theuniformity of duration of the flashes and the progressive decrease ofthe spaces therebetween, the time interval represented by these bandsbeing equivalent to that embraced between the lines a, b as theyintersect the bands RR, GG, RR and GG of this chart.

Referring next to Fig. 3, it will be observed that there is heredisclosed an arrangement for operating a pair of flashing contacts H and'12 from a wheel 65 which differs in a number of respects from thearrangement of Fig. 2.

The cams iii and 32 are associated with contacts and 42 and are flxedupon the shaft 24 It should be understood that contacts corresponding to43 44 45 and 46 of Fig. 2, or structure providing equivalent functions,should be made operative incidental to rotation of the shaft 24 The pinsM2 and 322 are carried by the cams ill and 32 for cooperation with thelevers 9| and 92 so that, as the shaft 24 revolves, said levers will besuccessively engaged by saidpins and thereby swung through apredetermined path.

The levers BI and 92 are pivoted at 84 94 in comparatively closeproximity to the paths of the pins M2 and 322 respectively; and the freeends of the portions of said levers which extend from their pivots awayfrom the paths of said pins have secured thereto flexible members orstraps Ilil, I02 which extend around and are secured to the cam shapedmembers I03, I04 which are fixed upon the sleeves 36 and 31,respectively, which sleeves are loosely journaled upon the shaft H Thesprings 96 96 are so applied to the cams I03, I04 as to resilientlyoppose rotation imparted thereto when the pins 3| 2 and 322 act, oneafter the other, to swing their associated levers 9| and 92 The discsI05 and H16 are fixed upon the sleeves 36 and 31, respectively; and,hence, are journaled upon the shaft GI and rotate with the cams I03 andI04, respectively.

The ratchet wheels I01 and I08 and the wheel 65 are fixed upon the shaft5|, and the ratchet wheel I0! is connected with the disc I05 through theratchet dog I09, so that when the pin 3I2 acting through the lever 9Fand strap IOI causes rotation of the member I03, the wheel 65 will becaused to rotate therewith; but when the member I03 is rotated in theopposite, direction in response to its spring 96 the dog I09 will permitthe wheel 65 to remain unaffected thereby. A corresponding connection(not shown) enables the disc I06 to drive ratchet wheel I00.

The peripheries of the cam members I03 and I04 are of such contour thatthe movement imparted to the levers 9| and 92 by their respectivelyassociated pins 3I2 and 322 will cause rotation of their associated camsat a progressively increasing speed. As the teeth of the wheel 65 areall of the same pitch, it will therefore be evident that the rotation ofsaid wheel, resultant from the rotation of the shaft 24 will be at aprogressively increasing speed, so that the flashes .ofthe signal lampscaused by the actuation of the contacts H and I2 which result from suchrotation of wheel 65 will be of durations and will be separated byintervals both of which will progressively decrease, as indicated by theband 3- of the chart of Fig. 4.

Referring next to the arrangement diagrammatically indicated by Fig. 5,it will be observed that a signaling system embodying the structuralcharacteristics there indicated is suited for response to vehicle orpedestrian movements as well as being suited to coordination of activitywith other signaling equipment.

As in the instances of Figs. 2 and 3, certain of the equipment indicatedby Fig. 5 substantially corresponds in structure and function withsimilar parts which are hereinbefore described in detail, and it istherefore deemed unnecessary to here repeat such description.

The shaft 24 which is driven by the motor 2I through suitable reductiongearing 22 23 drives cams 20I, 202, 203, 204 and 205, in suitableangular relationships to cams 3", 32 33 and 34 which latter camssubstantially correspond with cams SP, 32 33 and 34 of Fig. 1.

The contacts 2, 2I2, 2I3, 2I4 and 2I5 are associated with the cams 20I,202, 203, 204 andv 205, respectively.

The periphery of cam 20I is so formed as to permit closure of contacts 2during those portions of each revolution of the shaft 24 when the teeth3| I and 32I of the cams 3I and 32 are being carried past the contacts4| and 42 respectively. The periphery of cam 202 is so formed as toeffect separation of contacts 2I2 during and substantially throughouteach closure of contacts 2I I, as permitted by cam 20I, and for furthereffecting separation of contacts 2I2 during a. portion of each occasionwhen cam 33 permits closure of contacts 43 The purposes of such controlsof contacts 2 and 2I2 will be hereinafter more fully explained.

The periphery of cam 203 is so formed as to permit closure of contacts2I3 just prior to that separation of contacts 2| 2 which occurs duringclosure of contacts 43 The periphery of cam 204 is so formed as topermit closure of contacts 2 I4 throughout each revolution of shaft 24other than for a brief interval shortly after cam 34 has permittedclosure of contacts 44 and the periphery of cam 205 is so formed as topermit closure of contacts 2I5 only during the early portion of thatpart of the revolution of shaft 24 during which cam 3I permitscontinuous closure of contacts M for reasons which will be hereinaftermore fully explained.

It will be understood by those skilled in this art that adjustment maybe effected of the relative durations of those portions of the operativecycle which are permissive for trafllc movements along the Main andCross thoroughfares by varying the angular extent of the raised portionsof cams 33 and 34 and of the solid raised portions of the cams 3| and 32through the utilization of well-known expedients. The presence offacilities for effecting such adjustments is diagrammaticallyrepresented by the pointer handle 22I and the associated bars 222, 222.

Associated with the controller C just described, there is provided arelay having a magnet 23I, together with sets of contacts 232 and 233;an adaptation switch 250; a flasher 234, which may be of any well-knownand commercially available type having facilities for effectingintermittent interruptions of current flow therethrough as, for example,a so-called thermo-flasher; and tramc responsive equipmentcomprising atransformer having a primary winding 24I, a secondary winding 242, anassociated bridge rectifier 243, a relay having a winding 244 suppliedthrough said rectifier, to control the set of contacts 245 and move thecontact 241 into engagement with the contact 246 and thereby force itaway from contact 248.

Signal lamps situated at the highway intersection S are responsivelyconnected with the controller C and the so-called master controller"shown at M is provided for coordinating the operation of the localcontroller C with that of other local controllers. It will, however, bereadi ly understood that a local controller, such as C may be operatedindependentlyof any master controller, as will be hereinafter more fullyexplained.

The master controller M comprises a motor 260 which acts throughsuitable reduction gearing 26I and 262, to drive the disc or cam 263,for controlling the pair of contacts 264 in such manner that saidcontacts will be caused or permitted to close for a suitable andpreferably brief interval during each revolution of said disc.

An adjustable resistance 265 affords facilities for effecting variationsin the speed of the operation of motor 260, and a second adjustableresistor 266 is provided for eflecting variations in the speed of themotors of associated local controllers, as will be hereinafter morefully explained.

The double pole three-way switch 250 comprises the arms ,25I and 252,the contacts 253, 254 and 255 associated with arm 25I, and the contacts256, 251 and 258 associated with arm 252; the arms 25I and 252 beingconnected by the insulating link 259 for simultaneous movement, forpurposes which will be hereinafter more fully explained.

The conductors 40I, 402 convey energy from a suitable source of electricpower supply to the signal lamps provided at the highway intersection Sand to the transformer primary winding 24I, through conductors asfollows: conductor 403 connects conductor 40I with one terminal each ofthe amber signal lamps A A A A conductor 404 connects conductor 40I withone of the contacts 232. and conductor 405 connects the other of saidcontacts with one of the terminals of each of all of the remainingsignal lamps. Conductor 406 connects conductor 40! with one terminal oftransformer primary winding 24! and conductor 40! connects the otherterminal of said winding to conductor 402. Conductor 408 connectsconductor 402 to one of the contacts of each of the pairs 2 I5, 4!, 4243 and 44 and, through a flasher 234 to one of the contacts of pair 233;the other contact of said pair being connected through conductor 400with the remaining terminals of amber lamps A, A, A, A", and theremaining contact of the pair 2!5. Conductor 55 connects the remainingone of the contacts of the pair 4! with the remaining terminals of theMain thoroughfare red lamps R R and the conductors 56 51 and 58correspondingly connect the remaining contacts of the pairs 42, 43 and44 with the remaining terminals of the Cross" thoroughfare red lamps R,R, the Main" thoroughfare green lamps G, G, and the Cross thoroughfaregreen lamps G, G, respectively.

The conductors 42! and 422 supply power from a suitable source to themaster controller M, and electrical connections are provided within saidcontroller as follows: conductor 43!, which serially includes adjustableresistor 265, connects supply conductor 42! with one terminal of motor260, and conductor 432 connects the other terminal of said motor toconductor 422. One terminal of adjustable resistor 266 is connected toconductor 42!, and conductor 433 connects the other terminal of saidresistor with terminal 442 of local controller C Conductor 434 connectsconductor 422 with terminal 44! of the local controller, and conductors435 and 436 connect the respective contacts of the pair 264 withterminal 443 of said local controller and supply conductor 42!,respectively. Conductor 43! connects supply conductor 42! with terminal444 of said local controller C It will be understood that conductors 42!and 422 may be connected with the same source of electrical energy asconductors 40! and 402, or to a different source, as convenience mayrequire.

Conductors are provided in local controller C in association withterminals 44!, 442, 443 and 444 thereof, as follows: conductor 45!connects terminal 44! to one terminal of the motor 2l and conductor 452connects the other terminal of said motor directly with one of thecontacts of each of the pairs 2!2 and 2!3, and serially throughadjustable resistor 453 with one of the contacts of pair 2! conductor454 connects conductor 45! with one end of relay winding 23!, and theother end of said winding is connected through conductor 455 to an endof conductor 456, the other end of said conductor 456 being connected toterminal 444; conductor 45! connects conductor 456 to the remainingterminal of pair 2!!; terminal 442 is connected to contact 256 of switch250 through conductor 458 and through conductor 450 to the other of thecontacts of pair H2; and conductor 459 connects contact 254 of saidswitch to terminal 443; said contact 254 being also connected, throughconductor 460 to contact 258 of said switch.

Dotted lines are shown proceeding from terminals 44!, 442, 443 and 444,which lines are representative of conductors which may be supplied forcorrespondingly connecting similar terminals of other local controllers.

One of the relay contacts 245 is connected through conductor 46! withswitch arm 26! and is also connected through conductor 482 with theremaining one of the contacts 2"; the other one of the pair 245 of relaycontacts is connected through conductor 463 with switch arm 262.

One end of transformer secondary winding 242 is connected throughconductor 464 with traflic responsive circuit controllers TRC, 'IRCwhich are situated in the path of traflic approaching the intersectionalong the The other end of transformer secondary winding 242 isconnected through conductor 465 to one of the alternating current inputterminals of bridge rectifier 243, the other A. C. input terminal ofsaid rectifier is connected through conductor 466 to relay contact 246.Relay contact 24! is connected through conductor 46! to one of the pairof contacts 2, and the other contact of said pair is connected to theintermediate terminal of transformer secondary 242 through conductor468. Conductor 469 connects relay terminal 248 with remaining terminalsof traffic responsive circuit controllers TRC, 'I'RC. Conductors 410 and41! connect the ends of relay winding 244 with the D. C. outputterminals of bridge rectifier 243, respectively.

Relay contacts 232 are so associated with winding 23! as to be closedresponsive to efl'ective energization of said winding; and contacts 233are so associated as to be open during such energization.

Contacts 245 are so associated with relay winding 244 as to be closedresponsive to effective energization of said winding, and contact 24! isso associated as to be moved into engagement with contact 246 responsiveto such energization and thereby causing the separation of contacts 246and 248.

The operation of a system arranged in accordance with Fig. 5 is asfollows:

Assuming that the arms 25! and 252 of adaptation switch 250 are restingupon contacts 253 and 256, respectively, and that suitable electricalenergy is applied to conductors 40!, 402, 42! and 422, the controller Cwill be rendered traffic re sponsive, and will operate independently ofmaster controller M. Relay winding 23! will be energized through acurrent path extending from power supply, through conductors 42! and 431to terminal 444, and thence through conductors 456 and 455 to one end ofsaid winding; and thence through said winding and from the other endthereof through conductors 454 and 45! to terminal 44! and thencethrough conductors 434 and 422 to the power supply. The resultantenergization of winding 23! will cause separation of contacts 233, andclosure of contacts 232. Such closure of contacts 232 will complete acurrent path from the power supply through conductors 40! and 404,through contacts 232 and conductor 405 to one of the terminals of eachof the signal lamps R R G G, R, R05, G05 Gc5 When the parts responsiveto rotation of shaft 24 are positioned as shown by the drawing, signallamps 1%, R and G, G will be lighted, through current paths renderedeffective at contacts 42 and 43 as hereinbefore more fully described,and motor 2 will be energized through the establishment of a currentpath from the power supply through conductors 42! and 43! to terminal444, thence through conductors 456 and 451, contacts 2!!, adjustableresistor 453, and conductor 452 to one terminal of motor 2! and from theother terminal of said motor through Cross thoroughfare. L

conductor 45| to terminal 44|, and thence through conductors 434 and 422to the power pp y- The energization of motor 2|, through the currentpath just indicated, will cause rotation of the shaft 24 therebybringing one after another of the notches between the teeth 4H of cam 3|into the path of the co-operating one of the contacts 4| to therebycause flashing of the signal lamps R3 R as hereinbefore more fullyexplained.

After the final one of the teeth 3| I has been thus withdrawn from theco-engaging one of the contacts said contacts will be and remain closedthroughout approximately one-half of a revolution of the shaft 24 Uponrotation of the cam 3| to the position which permits such continuousclosure of the contacts cams 202 and 205 will have been moved topositions permitting closure of their associated contacts 2|2 and 2 5,respectively, and cam 33 will have moved to a position where itseparates contacts 43 and, upon slight additional rotation thereafter,cam 20| will effect separation of its associated contacts 2| 7 Suchclosure of contacts 2|5 will cause lighting of the amber lamps A A, A A,through a current path as follows: from the power supply throughconductors 40! and 403 to one of the terminals of each of said lamps,from the opposite terminals of said lamps through conductor 409,contacts 2|5, and conductors 408 and 402 to the power supply. Theconcurrent separation of contacts 43 will cause extinguishment of signallamps G 6 Because of the circuits and conditions thus established, redand amber signals will be given to all traffic which, pursuant to therules effective in certain localities, establishes a so-calledpedestrian period during which pedestrians may move freely across theintersection, and vehicles are forbidden entrance thereupon.

The closure of contacts 2|2 established a connection from power supplyconductor 42| through adjust-able resistor 266 and conductor 433 toterminal 442, thence through conductor 450 and contacts 2|2 to conductor452; thus replacing the current path there interrupted at contacts 2| I,which path extends from power supply through conductors 42|, and 431 toterminal 444, and thence through conductors 456 and 451, to and throughcontacts 2| I, and adjustable resistor 453 to conductor 452.

After the pedestrian period signaling aspect just described has beenmaintained for a desired time, the continued rotation of the shaft 24will move the cams 205 and 32 to positions where they separate theirrespectively associated contacts 2|5 and 42 and the cam 34 willthereupon have moved to a position where it permits closure of contacts44 Such separation of contacts 2| 5 and 42 will cause extinguishment ofall of the amber signal lamps and of the Cross thoroughfare red signallamps, R, R, and such closure of contacts 44 will cause lighting of theCross thoroughfare green signal lamps G, G; since the Main" thoroughfarered signal lamps R R were previously lighted through continuous closingof contacts 4| there is thus provided a stop aspect for traflicapproaching the intersection along the Main thoroughfare and a go"aspect for traffic approaching the intersection along the Crossthoroughfare. Shortly after the commencement of this signaling aspect.the continued rotation of shaft 24 will cause the raised portion of cam204 to momentarily effect separation of its associated contacts 214, fora purpose which will be hereinafter more fully explained.

When such signaling aspects have been maintained for a desired time, thecontinued rotation of shaft 24 will withdraw the continuous raisedportion of cam 32 from contacts 42 so that flashing of the lamps R Rwill occur as the notches between teeth 32| are presented to theco-engaging ones of contacts 42 in the manner hereinbefore more fullyexplained. During such flashing of said lamps, the cam 20| will be sopositioned as to permit closure of contacts 2| and the cam 202 will beso positioned as to effect separation of contacts 2| 2, thereby placingthe speed of operation of the motor 2| in control of the adjustableresistor 453, instead of the adjustable resistor 266.

From the foregoing it will be apparent that the speed of the motor 2during the red flashing periods" may be varied by adjustment of theresistor 453, so that the time occupied by such flashing periods will bein accordance with the practical conditions obtaining at theintersection S without thereby effecting the extent of the times duringwhich trafiic movements are permitted along the Main and Crossthoroughfares, respectively.

Immediately after the final one of the teeth 3i2| has been withdrawnfrom the co-engaging one of the contacts 42 the continued rotation ofshaft 24 will carry cams 3| and 34 to positions where they will effectseparation of their respectively associated contacts 4| and 44 and willcarry cams 33 to a position where it permits closure of contacts 43thereby causing a stop signaling aspect for Cross thoroughfare trafllcand a go aspect for Main thoroughfare traffic, in the mannerhereinbefore more fully explained.

Shortly after the establishment of signaling aspects as just referredto, cam 203 will reach a position where it permits closure of itsassociated contacts 2|3, and cam 202 will thereupon I reach a positionin which its raised portion 202| will eifect separation of contacts 2|2.

Such separation of contacts 2|2 will interrupt the current paththeretofore supplying motor 2| and said motor will come to rest unlessan alternate current path is established through contacts 2|3, in amanner which will be more fully described. a

The traflic responsive circuit controllers indicated at TRC. TRC in theCross thoroughfare near the intersection S may be of any wellknown typeproviding facilities whereby pedestrians wishing to cross one of thethoroughfares at the intersection and/or vehicles approaching theintersection along the Cross thoroughfare, may effect closure ofnormally open contacts.

Upon closing the contacts of either of the circuit controllers TRC,'I'RC a current path is established from transformer secondary winding242, through conductor 464, through the closed contacts of such circuitcontroller TRC, through conductor 469, contacts 248 and 246, andconductor 466 to one of the A. C. input terminals of bridge rectifier243, and from the other input terminal of said rectifier throughconductor 465 to the other end of transformer secondary winding 242.Current will thereupon flow through the path just indicated because ofexcitation of primary winding 2 from the power supply tion of winding244, as-J'ust described, an ener-' through conductors 401 and 406 to oneend of said winding 241, and from the other end of said winding throughconductors 401 and 402 to the power supply.

The alternating current flow through bridge rectifier 243 resultant fromclosure of one of the circuit controllers TRC, TRC will cause direct,

current energization of relay winding 244, because of theconnection ofthe ends of said winding through conductors 410 and 411 with therespective direct current output terminals of bridge rectifier 243.

Such energization of relay winding 244 will cause contact 241 to moveinto engagement with contact 246 and move the latter away from contact248; and will, at the same time, causecontacts 245 to close.

When contact 241 is thus brought into engagement with contact 246, aso-called lock-up" current path for relay winding 244 is established,which excludes a portion of transformer secondary winding 242 andconductor 464, controllers one of the A. C. input terminals of bridgerectifier 243, and from the other A. C. terminal of said rectifier,through conductor 466, contacts 246 and 241, conductor 461, contacts 214and conductor 7 468 to the intermediate terminal of transformersecondary winding 242; thereby effecting energization of relay winding244, through the action of the rectifier 243, and the conductors 410 and411.

If contacts 213 are closed at the time that contacts 245 are closedresponsive to energize.-

gizing current path for motor 21 will be established from the powersupply through conductor 421,v adjustable resistor 266, conductor 433 toterminal 442, thence through conductor 458 to adaptation switch terminal256, thence through arm 252, conductor 463, contacts 245, conductor 462to contacts 213, thence through conductor 452 to one terminal of saidmotor. From the other terminal of the motor such current path leadsthrough conductor 451 to terminal 441 and thence through conductors 434and 422 to the power supply, thereby establishing a path which willcause starting and operation of motor 21 If, however, the contacts 213are open at the time that contacts 245 are closed, operation of motor 21will be maintained through the current path provided through conductor452, contacts 212, and conductor 450 to the aforesaid terminal 442 untilcontacts 213 have closed, after which the operation of said motor 21will be maintained through the current path including contacts 213, asjust referred to, notwithstanding opening of contacts 212 by raisedportion 2021 of cam 202, and the cycle of operation hereinbefore morefully explained will be repeated.

During such cycle of operation, and shortly after establishment of asignaling aspect permissive for vehicles approaching the intersectionalong the "Cross thoroughfare, the raised portion of cam 204 will bebrought into engagement with and cause separation of contacts 214,thereby interrupting the loclr-up current path for relay winding 244;whereupon contacts 245 will be opened and contact 241 will move awayfrom contact 246, permitting the latter to move into engagement withcontact 248; whereupon, the ensuing rotation of shaft 24 will quicklywithdraw the raised portion of cam 204 from contacts I 214 permittingsaid contacts to close and thereby rendering the lock-up circuiteffective for maintaining energization of winding 244 following the nextsucceeding closure of a contactor TRC. k

Next assuming that the arms 251 and 252 of adaptation switch 250 areresting upon contacts 254 and 251, the controller C will be responsiveto master controller M, and will operate independently of the circuitcontrollers 'I'RC, TRC.

In other words, after the motor 21 has become deenergized, because ofthe separation of the contacts 21 1 by cam 201 and the concurrentseparation of contacts 212 by the raised portion 2021 of cam 202,reenergization of said motor will be effected upon closure of contacts264 of master controller M through a current path from power supplythrough conductors 421 and 436, through contacts 264, and conductor 435to terminal 443; thence through conductor 459, contact 254, switch arm251, conductor 461, conductor 462, closed contacts 213, and conductor452 to a terminal of said motor.

During such operation, the resistors 265 and 266 should be so relativelyadjusted that the speed of disc 2651 will be somewhat less than that ofshaft 24 in orderthat the motor 21 will become deenergized whenever theraised portion 2021 of cam 202 effects separation of contacts 212, andsaid motor 21 will be thereafter reenergized when the raised portion ofcam 263 is withdrawn from contacts 264, permitting closure of saidcontacts.

It will be evident that if it is desired to lengthen the duration of thego signaling aspect for the Main thoroughfare, this can be accomplishedby decreasing the speed of motor 260, through adjustment of resistor265. If it is desired to increase the duration of go" signaling aspectfor the Cross thoroughfare, this can be accomplished by decreasing thespeed of motor 21 by suitable adjustment of resistor 266; which changein speed will not, however, be effective during the flashing redperiods, as motor 21 is then supplied through adjustable resistor 453instead of adjustable resistor 266 during such periods.

When the switch arms 251 and 252 of switch 250 are resting upon contacts255 and 258, the controller C will be rendered responsive to actuationof contactors 'I'RC, TRC only during closures of master controllercontacts264; so that, so long as said controllers TRC, TRC are notoperated, a go signaling aspect may be given for traffic approaching theintersection along "Main thoroughfare; and following actuation of eitherof said controllers TRC, TRC, energization of motor 21 and consequentrotation of shaft 24 will be initiated only at a time when contacts 264of master controller M'have closed; to the end that if a number of localcontrollers are associated with the master controller M, the controllerC will effect discontinuance of the go signaling aspect for ,Mainthoroughfare traffic only upon occasions which have intended timer.relation to the operation of master controller M.

From the foregoing it will also be apparent that, if the arms HI and 252are positioned as previously described upon contacts 253 and 256, themaster controller M need not be supplied; in which event the adjustableresistor 266 may, if needed, be inserted between terminal 442 andconductors 450 and 458.

As previously explained, the relay winding 23f receives energizationthrough a current path extending from power supply, through conductors42l and 431 to terminal 444, and thence through conductors 456 and 455to and through said winding, through conductors 454 and 4M to terminalI, and thence through conductors 434 and 422 to power supply.

From the foregoing it will be apparent that in situations whereconductors 4M and 402 are connected to a power supply other than thatwhich supplies conductors 42l and 422, failure of such supply to causeeifective energization of relay winding 23!, would permit contacts 232to separate and contacts 233 to close.

Since, as previously explained, connection of the power supply to thelamps R R G 6 R, R, G, G is dependent upon closure of contacts 232, itwill be evident that the separation of contacts 232 will cause theextinguishment of any of such lights which would otherwise be lightedthroughout such time. Furthermore, the closure of contacts 233 causesthe amber lamps A A A A to be lighted through the establishment of acurrent path as follows: from power supply through conductors 40l and403 to one terminal of each of said amber lamps, thence, through saidlamps and from the remaining terminals thereof through conductor 409,contacts 233, conductor 408 and flasher 234 to and through conductor 402to the power supply.

The inclusion of flasher 234 in the current path just traced causes, ina well-known manner, an intermittent lighting or flashing of the amberlamps which, pursuant to the rules effective in certain localities,establishes a so-called caution" signal.

It will be apparent to those skilled in this art that variousre-arrangements of cam periphery configurations, contacts and'electricalconnections may be made, pursuant to this invention so as to providedifferent signalling aspect cycle components such, for example, as areindicated by the charts of Figs. 6, '7, 8 and 9.

Fig. 6 is a chart indicating a cycle having a period in which a green orgo" signaling aspect is provided for Main thoroughfare traflic, duringthe latter portion of such period a flashing amber aspect isconcurrently provided which is followed by a steady amber aspect whichcommences before the termination of the green aspect and persists for ashort time thereafter and until the commencement of a steady red aspect;a corresponding cycle of color changes in reverse order being providedfor the "Cross thoroughfare.

The chart of Fig. '7 indicates a color cycle for each thoroughfarecomprising a steady green portion which persists until the commencementof a steady red portion, a flashing green portion being providedconcurrently with the early part of the red portion.

The chart of Fig. 8 shows a color cycle comprising a steady greenportion, followed by a flashing green portion, which, in turn, isfollowed by a steady red portion.

The chart of Fig. 9 indicates a cycle for each thoroughfare comprising asteady green portion during the latter part of which there is a flashingamber period followed by a steady amber period, and following the greenportion there is a second flashing amber period followed by a steadyamber period, following the termination of which there is a steady redportion.

Obviously, other structures may be devised which may embody theinvention herein set forth. The drawings and description thereof aretherefore to be considered in an illustrative and not in a limitedsense; and it should be understood that the language used in thefollowing claims is intended to cover all of the generic and specificfeatures of the invention herein described and all statements of thescope of the invention, which, as a matter of language, might be said tofall therebetween.

ed with said conductors for operation from said source and foralternately closing respective current paths for said lamps continuouslythroughout desired intervals measured by the running of said mechanism,in combination with means operable responsive to running of saidmechanism during continuous closure of the connection for said "go" lampfor repeatedly effecting a series of comparatively brief closures of theconnection to said stop lamp, the durations of said closures and of thetime intervals therebetween progressively decreasing, to indicate theincreasing proximity of the termination of such continuously effectiveclosure.

2. In a signaling system, a source of electrical energy, stop" and gosignaling lamps, conductors for operatively connecting said lamps withsaid source, circuit controller mechanism associated with saidconductors-for operation from said source and for alternately closingrespective current paths for said lamps continuously throughout desiredintervals measured by the running of said mechanism, in combination withmeans operable responsive to running of said mechanism during continuousclosure of the connection for said "go lamp for repeatedly effecting aseries of comparatively brief closures of the connection to said stoplamp, said closures separated by time intervals of progressively.decreasing duration, whereby to indicate the increasing proximity ofthe termination of such continuously effective closure.

3. In a signaling system, a source of electrical energy, stop and "gosignaling lamps, conductors for operatively connecting said lamps withsaid source, circuit controller mechanism associated with saidconductors for operation from said source and for alternately closingrespective current paths for said lamps continuously throughout desiredintervals measured by the running .of said mechanism in combination withmeans operable responsive to running of said mechanism during andadjacent a terminus of the continuous closure of the connection for oneof said lamps for repeatedly effecting a series of comparatively briefclosures of the connection to the other of said lamps, which connectionsare effective for time intervals, measured by the running of saidmechanism and of progressively decreasing duration.

plurality of signaling aspects, each aspect eflective between somepredetermined termini for indicating occasion for permissive andrestrictive governing of an activity; circuit controller mechanismassociated with said means for rendering said aspects alternatelyeffective throughout intervals measured by the running of saidmechanism, in combination with means operable at a progressivelyincreasing speed for causing intermittent display of a signaling aspectat a progressively increasing frequency and for progressively decreasingdurations during and adjacent an interval terminus whereby to indicatethe proximity of said terminus.

5. In a signaling system, signals for displaying diverse aspects, eachaspect effective between some predtermined termini for indicatingoccasion for permissive and restrictive governing of an activity,mechanism operable for establishing times for varying the display 01'said signaling aspects,

in combination with means for effecting, during a portion of the displayof one of said signaling aspects, a series of comparatively briefdisplays of another of said signaling aspects and whereby said briefsignal displays will be separated by time intervals of progressivelydecreasing duration, whereby to indicate the increasing proximity of theimpending change.

6. In a traflic signaling system comprising signals having diverseaspects for governing traflic movements, means operable for eflectingdisplays of said signals in accordance with a predetermined sequence ofpresentation, in combination with means for effecting intermittentdisplay of one of said signals, for indicating the proximity of a changeof signal display pursuant to said sequence of presentation, suchintermittent displays characterized by progressive decreases ofdurations and of time intervals therebetween.

7. In a traflic signaling system comprising signals having diverseaspects for governing traific movements, means operable for eflectingdisplays of said signals in accordance with a predetermined sequence ofpresentation, in combination with means for effecting intermittentdisplay of one of said signals for indicating the proximity of a changeof signal display pursuant to said sequence of presentation, suchintermittent displays characterized by progressive decreases of thedurations thereof.

ERNEST R. FREEBERG.

